- In geometry, a polyhedron (pl.: polyhedra or polyhedrons; from Greek πολύ (poly-) ‘many’, and ἕδρον (-hedron) ‘base, seat’) is a three-dimensional shape with flat polygonal faces, straight edges and sharp corners or vertices.
- Bab-el-Mandeb (Wikipedia)
The Bab-el-Mandeb (Arabic: باب المندب, lit. ‘Gate of Lamentation’, Tigrinya: ባብ ኣል ማንዳብ), the Gate of Grief or the Gate of Tears, is a strait between Yemen on the Arabian Peninsula and Djibouti and Eritrea in the Horn of Africa. It connects the Red Sea to the Gulf of Aden and by extension the Indian Ocean.